Chris Kresser: One thing is, when you said B12, folate, and hemoglobin are normal, is that just serum B12, or did you also check methylmalonic acid either in the serum or the urine and also homocysteine? Because those are more sensitive markers for B12 deficiency. We’re going to talk about that in the blood chemistry unit, but I mention it here because I’d want to check and see what’s happening with B12 levels, for sure. Then as far as why the vitamin D is going down, it’s possible that the 1,000 IU dose was just inadequate and the last three months have been winter, so she was probably getting even less sun exposure, so it could be that even with that dose of vitamin D, it’s not adequate, especially during the winter months. Also it could be that she’s not absorbing that form of vitamin D if she’s taking a capsule and she has gut-related issues. With a really low vitamin D level like that, I would be using a much higher dose initially. I would use something like 10,000 IU, and I would take a whole-food form like cod liver oil as well as a supplemental form, and I would use a micellized form of vitamin D, like a liquid where it’s predigested and they just put it under their tongue and get much higher absorption through that. That’s related to vitamin D.
Then in general, there’s a very strong connection between psychosis and a variety of gut conditions, so I would make sure that you’re checking and doing a full gut workup, as we’ve talked about so far in the course. Chris Masterjohn gave a really interesting talk at the UCSF symposium, suggesting that low levels of vitamin D that are below what are considered to be the low end of the reference range can sometimes be normal. There are a lot of reasons for this, and it’s usually in non-whites. There’s a study, for example, of non-white people with abundant sun exposure living in Hawaii, and it showed that they had average vitamin D levels that were below the 30 nanograms per milliliter, which is the low end of the reference range in the US. Blacks, on average, have lower vitamin D levels than whites, but their bone mineral density, on average, is higher. Chris Masterjohn is one of the most knowledgeable people in this field, and his argument was that there are genetic differences that affect the activation of 25(OH)D, which is the precursor form, into the active form, which is calcitriol, 1,25D. Some people, particularly people of non-white ancestry, may require less 25(OH)D to produce the same amount of 1,25D. So if you see low 25(OH)D levels, and the patient particularly is of non-white ancestry, then it’s probably a good idea to test calcitriol levels, 1,25D levels, and also parathyroid hormone levels. I’m going to be giving you an algorithm when we get to the blood chemistry section. I’m going to give you an algorithm for looking at 25(OH)D, 1,25D, and parathyroid hormone levels to determine if biological vitamin D deficiency is present, and if it is, what to do about that, depending on what the ethnicity of the patient is.
Having said that, 10 nanograms per milliliter is almost certainly deficient. There’s no even non-white population that has average D levels that are that low, and so I feel pretty safe in recommending supplementation for that person.